A self-determining control circuit is generally one in which the circuit can automatically determine its state of operation and perform control operations accordingly. For example, U.S. Pat. No. 6,188,273 describes an integrated circuit that includes a contact-making point for selecting an operating mode of the integrated circuit. The contact-making point can be connected to one of two different supply potentials. The integrated circuit has a control device that is connected to the contact-making point that identifies which of the two supply potentials the contact-making point is connected and generates a corresponding operating signal.
If an electronic control circuit is to be able to assume more than two operating modes, however, it typically includes either further inputs for selecting the operating mode, for example as described in U.S. Pat. No. 6,157,051, or more than two supply potentials must be provided. The addition of inputs or power supply potentials may add size or cost to the circuit.
It is one object of the present invention to provide a self-determining electronic circuit that can assume several different states, or can permit several different operating modes, depending on the interconnection (or lack thereof) of at least one input with at least one output of the circuit. Such a circuit is thus enabled to assume two or more operating modes without the provision of additional inputs or power supply potentials.